JPS63265736A - Control device for traveling of vehicle - Google Patents

Abstract

PURPOSE:To automatically select a constant speed traveling controllable area even on an ascent in addition to constant speed traveling on a flat road traveling by distinguishing a slope from a flat road through the output level of a deceleration sensor. CONSTITUTION:Deceleration signals from a vehicle speed sensor 23 and a G sensor 24 are inputted into a microcomputer control unit 31. When an inputted deceleration is judged to be above a previously set first reference value, an ascent is detected. And, by checking whether an ascent was detected in an interruption processing one cycle before and when it was not detected, judgment is formed to be immediately after entering an ascent. And, when the deceleration of a vehicle is above the first reference value and below a second reference value, the vehicle speed at the time of operating a resume switch is stored in a RAM 39 as a target vehicle speed Vc for constant speed traveling on an ascent. Further, when the deceleration becomes above the second reference value, a brake pressure is controlled by steps between the lowest brake pressure and the highest brake pressure with respect to the deviation in vehicle speed, to deceleratingly control the target vehicle speed for constant speed traveling.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention corresponds to road conditions and enables appropriate switching control between constant speed running control, deceleration running control, and manual running, and is particularly suitable for driving on straight roads, loose roads, etc. This relates to a vehicle travel control device that operates in a constant speed driving mode on slopes, corrects the target vehicle speed when the inclination angle of an uphill slope exceeds a predetermined value, and also uses brake control when the vehicle speed deviation increases on a downhill slope. .

[Conventional technology]

Conventionally, from the viewpoint of safe driving, constant speed control devices for vehicles have generally been used only when driving on flat roads.

FIG. 5 is a system block diagram of a conventional constant speed cruise control device. In FIG. 5, 23 is a vehicle speed sensor for detecting vehicle speed, 25 is a brake switch activated by brake operation, 27 is a set switch that outputs a set signal by driver operation, and 29 is also activated by driver operation. A resume switch that outputs a resume signal is connected to a microcomputer (hereinafter referred to as microcomputer) control unit 310 and an input/output board 41.

Further, the microcomputer control unit 31 outputs an opening degree control signal to a throttle related control device 33 that adjusts the opening degree of a throttle valve (not shown) to control the vehicle speed.

Note that the microcomputer control unit 31 includes a CPU 35, R
The configuration includes an OM 37, a RAM 39, and an input/output port 41.

Next, the operation of the conventional device will be described. First, the vehicle speed V is input from the vehicle speed sensor 23 to the microcomputer control unit 31 .

When the driver turns on the set switch 27 in this state,
The vehicle speed at that time or the target vehicle speed V. After that, the vehicle speed is made to follow this target vehicle speed, and the throttle opening fttlJ control device 33 is fully controlled so that the throttle opening is proportional to the vehicle speed deviation.

By the way, the conventional device does not have a special sensor for distinguishing between a flat road and an uphill road, so if the driver makes a judgment based on his senses and determines that it is possible to drive at a constant speed on a substantially flat road,
The vehicle was traveling at a constant speed with the set switch 27 turned on and the vehicle speed at that time set as the target vehicle speed, and constant speed traveling control is generally not performed on the uphill road.

Further, when the vehicle enters a hill on a flat road with constant speed driving control set, constant speed driving control is canceled only by the driver's brake operation.

Furthermore, if the resume switch 29 is erroneously operated on the uphill road, the constant speed cruise control will be set, and thereafter the constant speed cruise control cannot be canceled unless the brake is operated as in the case described above.

[Problem that the invention seeks to solve]

That is, in the conventional example, there is no other way to release the fail-self mechanism other than by operating the brake switch by operating the brake.

This invention was made in order to solve this problem, and it is possible to use the constant speed driving control applied on flat roads also on general uphill roads, and is expected to expand the utilization efficiency of the constant speed driving control device. An object of the present invention is to obtain a vehicle running control device that can further improve safe running performance.

[Means for solving problems]

The vehicle running control device according to the present invention includes a deceleration sensor that detects and outputs deceleration on a slope, and performs constant speed running control, correction of target vehicle speed, and brake control according to the level of the detection output of this deceleration sensor. A vehicle speed control means for controlling the combined use is provided.

[For production]

In this invention, the deceleration state of the vehicle is detected by the deceleration sensor, and when this detection output level exceeds the first reference level, it is determined that the road is uphill, the driving mode is reset to the initial state, and the deceleration sensor When the output level of the deceleration sensor exceeds the first reference level and is less than the second reference level, constant speed driving control is enabled at a set vehicle speed with the upper limit of the vehicle speed at the time the resume switch is operated, and the output level of the deceleration sensor is exceeds the second reference level, the target vehicle speed for constant speed driving is corrected according to the degree of deceleration of the vehicle, and constant speed driving is controlled even if the regular route approaches the downhill slope of the uphill road. continues, but if the speed deviation exceeds a predetermined reference value,
After decelerating to a safe driving speed using brake control, the vehicle returns to manual mode.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the vehicle travel control device of the present invention will be described below with reference to the drawings. FIG. 1 is a system block diagram of one embodiment. In FIG. 1, parts that are the same as those in FIG. 5 are given the same reference numerals, and parts that are different from FIG. 5 will be mainly described.

The difference between FIG. 1 and FIG. 5 is that a deceleration sensor 24 (as an uphill road detection means) is used to detect vehicle deceleration.
The G sensor) is connected to the input port of the mic 7j (jlJ control unit 310), and the brake control device 34 is newly connected to the output boat.Other parts are the same as in Fig. 5. It is.

Next, the control action of this invention will be described. First, a vehicle speed signal from the vehicle speed sensor 23 and a deceleration signal from the G sensor 24 are input to the microcomputer control unit 31 .

Next, it is determined that the input deceleration is equal to or higher than a first preset reference value, and the climbing road is detected, and at the same time, it is checked whether the climbing road was detected in the interrupt processing one cycle before, If not, it is determined that the vehicle has just entered the boarding road, and if the deceleration of the vehicle exceeds the first reference value and is below the second reference value, the vehicle speed at the time the resume switch is operated is determined. It is stored in the RAM 39 as a target vehicle speed vc for constant-speed driving on a boarding road, which will be described later.

Next, if an uphill road is currently being detected, while traveling on this uphill road,
It is determined whether the resume switch 29 has ever been turned on, and if it has been turned on, the mode is set to constant speed running mode at that point, and if it is up to 1 (off), the mode is set to manual mode.

Further, when the deceleration of the vehicle exceeds a second reference value while the vehicle is traveling in the constant speed driving mode, the target vehicle speed of the constant speed driving can be corrected and controlled in accordance with the deceleration.<fc (e.g., decreasing target vehicle speed as deceleration increases).

Furthermore, it is determined whether or not the set switch 27 is turned on while driving on a flat road, and if it is turned on, it is set to constant speed driving mode, and if it remains off, Set to manual mode.

Next, even when the slope of the climbing road approaches a downhill slope, the constant speed driving mode is continued, but when the vehicle speed deviation increases and its value exceeds a predetermined reference value, the constant speed driving mode is canceled.
The vehicle is set to deceleration driving mode, and the brake control device is activated to decelerate the vehicle to a predetermined safe speed. At this point, vehicle speed control is canceled and the vehicle returns to manual mode.

In the case of constant speed driving mode on the boarding road, the vehicle speed V and the target vehicle speed V are set in order to drive at a constant speed at the target vehicle speed vc stored in the RAM 39. In the case of flat road constant speed driving mode, the vehicle speed at the time when the set switch 27 is activated is set as the target vehicle speed vc, and the opening control signal is set to the throttle as in the case described above. It is output to the opening control device 33 to control the vehicle speed.

FIG. 2 is a system block diagram showing a second embodiment of the invention. 2, the difference from the first embodiment shown in FIG. 1 is that the throttle sensor 28 for detecting the throttle opening is connected to the input port of the microcomputer control unit 310, and a The point is that a user cut device 36 is added to the output boat.

The difference between the operation of the second embodiment and the first embodiment is that in the deceleration control mode, the deceleration does not reach the safe running speed even after a predetermined period of time has elapsed after the start of the brake control, and the throttle opening is When the opening degree is below a predetermined opening degree, the fuel cut device 36 is operated to reliably reduce the vehicle speed to the safe running speed, thereby improving vehicle safety.
It is something.

Next, a specific embodiment of the brake control device in the deceleration traveling control mode will be described with reference to FIG.

Figure 3 shows the first part of the brake control device in deceleration traveling control.
This figure shows a block diagram of an embodiment of the present invention. In this FIG. 3, 101 is a wheel, 102 is a brake cylinder,
103 is a brake pedal, 104 is a mask cylinder, 1
04a is a high pressure boat of the mask cylinder, and 104b is a low pressure boat of the mask cylinder.

The high pressure port 104a is connected to the brake cylinder 102 via a hydraulic pipe 105a, a two-way solenoid valve 134, and a fixed orifice 122.

This hydraulic conduit 105C is provided with a pressure gauge 135 and communicates with the surge tank 120.

The low pressure port 104b of the mask cylinder 104 communicates with the reservoir tank 131 via the hydraulic line 105d, and the hydraulic tank 130 is connected to the hydraulic line 105b.

Solenoid variable orifice 121, hydraulic line 1051
It communicates with the reservoir tank 131 via. 121
a is a solenoid coil.

Hydraulic tank 130 has 2 sides and 1! It is connected to a hydraulic conduit 105C via a magnetic valve 132, and this hydraulic conduit 105C communicates with a reservoir tank 131 via a two-way solenoid valve 133.

Hydraulic pipe line 105C has three-way solenoid valve 112° and 114, respectively.
．． 116 input ports 112A, 114A, 116A, and its output ports 112B, 114B, 1
16B are hydraulic pipes 105e, 105f, and 105, respectively.
It is connected to pressure regulating tanks 113, 115, and 117 via g.

Each three-way solenoid valve 112, 114, 116 further communicates with a reservoir tank 131 via a hydraulic line 105tl.

Next, the operation of this brake control device will be described. In the normal braking state, the two-way solenoid valve 134 is in the on state,
Therefore, the mask cylinder hydraulic pressure corresponding to the amount of brake depression is supplied to the brake cylinder 102 through hydraulic lines 105a to 105c' (zfM), and a normal braking operation is performed.

In addition, in the brake off state, the high pressure port 104a of the mask cylinder 104 communicates with the low pressure port 104b, passes through the reservoir tank 131K via the hydraulic line 105d, and the brake operating pressure is released.

Next, in the deceleration running state, the 20,000-way solenoid valve 134 is turned off, the two-way solenoid valve 132 is turned on, and the hydraulic pressure of the hydraulic pump 130 is transferred to the hydraulic pipe 105b.

It comes to act on the brake cylinder 102 via 1osct-.

The pressure switch 135 is activated when the pump operating pressure reaches a predetermined pressure, and in response, the two-way solenoid valve 132 is turned off, so that the pump operating oil is sealed in the hydraulic conduit 105c.

Further, the input and output ports of the hydraulic pump 130 are communicated with each other through a solenoid type variable orifice 121, and a pump pressure determined by the diameter of this solenoid type variable orifice 1210 is set.

Next, the diameter of the solenoid-type variable orifice 121 is the same as that of the solenoid coil 121a! Since it is controlled by current, by controlling this coil current,
The pump pressure is configured to be freely adjustable within a predetermined range.

Next, when the three-way solenoid valve 112 is turned on, a portion of the pump hydraulic oil sealed in the hydraulic line 105C flows into the pressure regulating tank 113, so that a portion of the pump hydraulic oil sealed in the hydraulic conduit 105C flows into the pressure regulating tank 113. The degree of pressure reduction is determined based on this.

Furthermore, when the two-way solenoid valve 114 is turned on, the pressure regulating tank 1
15 becomes conductive, and when the two-way solenoid valve 116 is further turned on, the pressure regulating tank 117 is brought into conduction.

Therefore, in this embodiment, by controlling the number of conductive pressure regulating tanks, it is possible to control the brake cylinder pressure in steps. By appropriately controlling the number of conductive pressure regulating tanks, the brake pressure can be adjusted to the vehicle speed deviation Δ
Step control becomes possible in response to V.

FIG. 4 shows the brake control characteristics of the brake control device described above. When the vehicle speed deviation △V is ≦Δ■ku△■2, all three-way solenoid valves 112, 114, and 116 are turned on, and the brake pressure is the lowest pressure P1. becomes.

When the vehicle speed deviation ΔVz≦ΔV (Δv3), two of the three-way solenoid valves 112, 114, and 116 are selectively turned on, and the brake pressure is increased stepwise to P2.

When the vehicle speed deviation Δv3≦ΔV, the three-way solenoid valves 112, 114
116 selectively becomes conductive, and the brake pressure further increases to P3.

Additionally, a fixed orifice 122 and a surge tank 120
is for absorbing the surge pressure generated when the 3-way solenoid valve 132 is turned on and smoothing the rise of the brake operating pressure. A pressure relief valve is used to rapidly remove the water.

As stated above, the control action of this invention device can be summarized as follows.

(1) When driving on a flat road, constant speed driving control is performed in which the vehicle speed at the time the set switch is operated is set as the target vehicle speed.

(2) When the resume switch is turned on while traveling on an uphill road If the deceleration of the vehicle is less than the second reference value, constant speed driving is performed with the vehicle speed at the time of the resume operation being the target vehicle speed.

(3) When the resume switch is turned on while driving uphill, if the vehicle deceleration exceeds the second reference value, the target vehicle speed is corrected, and if the vehicle speed deviation exceeds a predetermined value while going downhill, the brake control device is activated. At the same time, under limited conditions where the throttle opening is below a predetermined value, the fuel cut control cuts off the fuel supply to the engine and decelerates the engine to a predetermined safe speed, then cancels the driving control and returns to manual mode.

〔Effect of the invention〕

As explained above, this invention uses the output level of the deceleration sensor to determine whether it is a flat road or a slope, and in addition to the conventional constant speed driving on flat roads, it also automatically controls the constant speed driving range on uphill roads. When selected, the deceleration of the vehicle is detected by a deceleration sensor, and if the detected value exceeds a certain level, the target vehicle speed is corrected, and if the vehicle speed deviation exceeds a predetermined value on a downhill slope, the vehicle is decelerated by brake control. mode, the vehicle is decelerated to a safe speed, and then returned to manual mode, implementing a travel control device with higher safety than conventional devices.

Further, in deceleration control, the brake pressure can be controlled in steps between the minimum brake pressure and the maximum brake pressure in response to the vehicle speed deviation, making it possible to perform brake control with improved control performance.

[Brief explanation of drawings]

FIG. 1 is a system block diagram of one embodiment of the vehicle travel control device of the present invention, FIG. 2 is a system block diagram of another embodiment of the vehicle travel control device of the present invention, and FIG. 3 is a system block diagram of an embodiment of the vehicle travel control device of the present invention. FIG. 4 is a brake control characteristic diagram of the above brake control device, and FIG. 5 is a system block diagram of a conventional constant speed cruise control device. 23... Vehicle speed sensor, 24... Deceleration sensor, 25
...Brake switch, 27...Set switch,
28... Throttle sensor, 29... Resume switch, 31... Microcomputer control unit, 33... Throttle opening control device, 34... Brake control device % 35... CPU, 36...・Fuel cut device, 37...ROM, 39...RA
M0 Note that the same reference numerals in the drawings indicate the same or similar parts.

Claims (2)

[Claims] (1) When the vehicle is driving on a slope, the deceleration sensor determines the degree of inclination angle, the vehicle speed sensor detects the vehicle speed, and the operation of the set switch and resume switch that output operation signals according to the driver's operation. means, when the vehicle is running on a flat road, enables constant speed running control at a set vehicle speed when the set switch is operated, and when the output of the deceleration sensor exceeds a first reference value, it is determined that the vehicle is running on an uphill road. When the resume switch is operated after resetting the driving mode to the initial state, constant speed driving control is enabled with the vehicle speed at that time being the target vehicle speed, and when the output of the deceleration sensor is greater than the first reference value, 2 If the reference value is exceeded, the target speed for constant speed driving is changed depending on the degree of deceleration, and even if the traveling road becomes a downhill slope, the constant speed driving mode can be continued. If the speed deviation increases and exceeds a predetermined reference value, the vehicle is set to deceleration driving mode, and the brake pressure is adjusted between the minimum brake pressure and the maximum brake pressure in conjunction with brake control using step control in response to the vehicle speed deviation. A vehicle running control device comprising vehicle speed control means that cancels vehicle speed control after decelerating to a safe running speed and restores to manual mode. (2) The vehicle speed control means determines whether the vehicle speed cannot be decelerated to the safe running speed even after a predetermined period of time has elapsed after the start of brake control when the throttle opening detected by the throttle opening sensor is below a predetermined value in the deceleration constant mode. 2. The vehicle running control device according to claim 1, wherein the vehicle running control device operates a fuel cut device when the vehicle is stopped.